During high speed operation of a pneumatic tire, such as on a race car tire mounted on a wheel, tire fill gas (typically air or nitrogen and hereinafter referred to as "air" or "gas") inside the tire expands. Tire pressure may increase to such an extent that operation or safety may be adversely affected. Air bleeders have been used to limit pressure in a tire by allowing air to escape at pressures above a set level. Bleeders are installed in the wheel, either in the valve stem hole or in a hole 180 degrees opposite the valve stem.
The tire bleeder described in U.S. Pat. No. 5,257,642 is one such bleeder manufactured by Aero-Weld. This bleeder is a round machined piece of aluminum approximately 5/8 inches in diameter and 3/4 inches long. It has a tapered seat, a poppet valve that is spring loaded against a knurled end cap. When the pressure inside a tire is high enough to overcome the spring pressure, the poppet valve opens, venting or bleeding air to the atmosphere. When sufficient air has escaped, the spring forces the poppet valve to close. The bleeder may be adjusted to a desired pressure by tightening or loosening an end cap. The end cap is locked in position by a lock nut.
A problem arises when the wheel is rotated at high speed. Centrifugal force works in an opposite direction of the bleeder poppet valve. That is, the centrifugal force from tire rotation is added to the spring force, thus requiring a higher tire pressure on the poppet valve before it can open, and not letting it bleed off air as desired at the set pressure. This increased pressure above the set pressure causes the tire to grow in size upsetting the balance of the race car.
Thus there exists the need for a method of regulating tire air pressure with a bleeder valve that is not affected by centrifugal force occurring when a tire is rotated at high speed.